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A systematic review and meta-analysis of more than 120 randomized trials offers new insight into the effects of weight regain on cardiometabolic risk up to 5 years after the cessation of a behavioral management program.
New research from investigators at the University of Oxford is shedding new light on the impact of weight regain on cardiometabolic risk following participation in a behavioral health management program.
An analysis of data from more than 120 trials in people with overweight or obesity, results of the study indicate, despite weight regain, behavioral weight management programs were associated with a reduction in cardiometabolic risk, with this reduction persisting for last least 5 years after the end of the program and becoming partly attenuated with weight regain.
“Many doctors and patients recognize that weight loss is often followed by weight regain, and they fear that this renders an attempt to lose weight pointless,” said senior investigator Susan A. Jebb, PhD, a professor of diet and population health at the University of Oxford in the United Kingdom.2 “This concept has become a barrier to offering support to people to lose weight. For people with overweight or obesity issues, losing weight is an effective way to reduce the risk of Type 2 diabetes and cardiovascular disease.”
Although the benefits of weight loss in people with overweight or obesity have been clearly elucidated, a common criticism of many of these studies is a lack of long-term follow-up examining effects following the cessation of the intervention period. With a specific interest in the impact of weight regain after behavioral interventions, a team led by Jamie Hartmann-Boyce, DPhil, of the Nuffield Department of Primary Care Health Sciences at the University of Oxford, designed the current study with the intent of examining the impact of weight regain on cardiovascular risk factors, diabetes, and cardiovascular disease.
To do so, investigators designed their study as a systematic review and meta-analysis of randomized controlled trials published in English examining behavior weight management programs in adults with overweight or obesity and reporting cardiometabolic outcomes at 1-year or beyond and after program end. Through a search of clinical trials registries and 11 electronic databases in September 2018, investigators identified 124 trials for inclusion in the current study.
The initial search returned 17,085 references and 4482 were selected for full-text screening. The group of 124 trials chosen for inclusion had a median follow-up of 28 (range, 11-360) months after program end, a median baseline participant BMI of 33 kg/m2, and a median age of 51 years. When examining risk of bias, investigators pointed out 52% of trials were at unclear risk of bias, primarily because they did not fully report randomization procedures, 27% were at low risk, and 22% were at high risk.
Results of the investigators’ analysis suggested incidence of cardiovascular disease and type 2 diabetes, which was evaluated in 8 and 15 study arms, respectively, was lower among those in behavioral weight management programs for at least 5 years following the end of the program. Further analysis suggested weight regain in these individuals reduced these differences.
When examining specific cardiovascular risk factors at 1 and 5 years after program end, results indicated total cholesterol/HDL ratio was 1.5 points lower at both times (82 studies; 19,003 participants), HbA1c was 0.38 percentage points lower at both times (94 studies; 28,083 participants), and systolic blood pressure was 1.5 mm mercury and 0.4 mm lower (84 studies; 30,836 participants) at the 1- and 5-year time points. Investigators highlighted removal of trials considered to be at high risk of bias did not result in a meaningful change in results.
“Our findings should provide reassurance that weight loss programs are effective in controlling cardiovascular risk factors and very likely to reduce the incidence of cardiovascular disease,” Jebb added.
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